Intervertebral implants, systems, and methods of use

ABSTRACT

An intervertebral implant frame that is configured to be attached to a spacer body can include a pair of arms that extend longitudinally from a support member such that the arms extend substantially around the spacer body. The arms may be configured to expand, crimp, or otherwise engage the spacer body to thereby hold the spacer body to the frame. The spacer body may be made from bone graft.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 13/333,065 filed Dec. 21, 2011, which claims the benefit ofU.S. Provisional Patent Application Ser. No. 61/425,505 filed Dec. 21,2010 and U.S. Provisional Patent Application Ser. No. 61/425,509 filedDec. 21, 2010, the contents of each of which are hereby incorporated byreference in their entirety herein.

BACKGROUND

Implants for spinal fusion typically include a spacer body to allow forgrowth of bone between adjacent vertebral bodies while restoring andmaintaining intervertebral space height that is defined between thevertebral bodies. In some cases, a plate is used to provide stabilityduring healing so as to allow the patient to quickly resume an activelifestyle. The profile of the plate, which is placed on the anterioraspect of the vertebral bodies, however, can lead to dysphasia orpatient discomfort which has resulted in various “zero-profile” devicescurrently being developed. For example, one zero profile device is anintervertebral device that is inserted into the intervertebral space.While the threaded device provides graft retention, stability in flexionand extension is questionable since the device does not positively lockto the vertebral bodies during implantation.

Other intervertebral implants have been utilized that include a frameshaped in a manner so as to hold a spacer body made from PEEK. Suchspacer bodies typically are customized to have complimentary features tothe frame so that the spacer bodies may be affixed to the frame. Suchframes may not be desirable for spacer bodies made from allograft,however, because allograft spacer bodies may vary in shape, may notinclude the complimentary features needed to be affixed to the frame,and may degrade or resorb overtime.

SUMMARY

In accordance with an embodiment, an intervertebral implant frame can beconfigured to support a spacer body in an intervertebral space that isdefined by a first vertebral body and a second vertebral body. Theintervertebral implant frame can include a support member having a bodythat defines first and second vertebral body facing surfaces, the secondvertebral body facing surface spaced from the first vertebral bodyfacing surface along a first direction. The body can further define atleast two fixation element receiving apertures that extend through thesupport member and are each configured to receive a respective bonefixation element. The implant frame can further include a first tab anda second tab that each extend from the first vertebral body facingsurface and are spaced from each other along a second direction that issubstantially perpendicular to the first direction so as to define a gapthat extends between the first and second tabs along the seconddirection, each of the first and second tabs being configured to abutthe first vertebral body when the intervertebral implant is inserted inthe intervertebral space. The frame can further include first and secondarms arm that extend from the support member and include, respectively,a first inner spacer contacting surface and a second inner spacercontacting surface that is spaced from the first inner spacer contactingsurface along the second direction such that the first arm and thesecond arm are configured to grip and retain the spacer body. The gapcan be configured to receive a portion of the first vertebral body wheneach of the first and second tabs abuts the first vertebral body.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofembodiments of the application, will be better understood when read inconjunction with the appended drawings. For the purposes of illustratingthe methods, implants and systems of the present application, there isshown in the drawings preferred embodiments. It should be understood,however, that the application is not limited to the precise methods,implants, and systems shown. In the drawings:

FIG. 1A is a perspective view of an intervertebral implant assembly thatis implanted in an intervertebral space defined by a superior vertebralbody and an inferior vertebral body, the intervertebral implant assemblyincluding an intervertebral implant and at least a pair of fixationelements that attach the intervertebral implant to the superiorvertebral body and the inferior vertebral body, respectively;

FIG. 1B is a side elevation view of the intervertebral implant assemblyas shown in FIG. 1A, the intervertebral space defining ananterior-posterior midline;

FIG. 1C is a top plan view of the inferior vertebral body shown in FIG.1B;

FIG. 2A is a perspective view of the intervertebral implant illustratedin FIGS. 1A and 1B, the intervertebral implant having an intervertebralimplant frame and a spacer body retained by the intervertebral implantframe;

FIG. 2B is a top plan view of the intervertebral implant shown in FIG.2A;

FIG. 3A is a perspective view of the intervertebral implant frame shownin FIG. 2, the intervertebral implant frame having a support member, afirst arm extending from the support member, and a second arm extendingfrom the support member, the first and second arms configured toelastically flex away from each other;

FIG. 3B is a front elevation view of the intervertebral implant frameshown in FIG. 3A;

FIG. 3C is a top plan view of the intervertebral implant frame shown inFIG. 3A;

FIG. 3D is a side elevation view of the intervertebral implant frameshown in FIG. 3A;

FIG. 3E is a cross-sectional view of the intervertebral implant frameshown in FIG. 3D through the line 3E-3E;

FIG. 4A is a perspective view of one of the fixation elements that isconfigured to affix the intervertebral implant shown in FIG. 2 to avertebral body as illustrated in FIGS. 1A and 1B;

FIG. 4B is a side elevation view of the of the fixation element shown inFIG. 4A;

FIG. 5A is a perspective view of a spacer body made from bone graft;

FIG. 5B is a perspective view of the spacer body shown in FIG. 2;

FIG. 5C is a top plan view of the spacer body shown in FIG. 5B;

FIG. 5D is a side elevation view of the spacer body shown in FIG. 5B;

FIG. 6A is a perspective view of an intervertebral implant systemconstructed in accordance with an embodiment, the system including anactuation instrument configured as an expansion instrument that includesan actuation grip illustrated as an expansion grip that is configured toactuate the frame shown in FIG. 3A from a first configuration to asecond configuration whereby the frame is configured to receive thespacer body shown in FIG. 5B;

FIG. 6B is a perspective view of the expansion instrument shown in FIG.6A, the expansion instrument including a first expansion arm and asecond expansion arm coupled to the first expansion arm at a firstpivot, each expansion arm having a handle portion and a gripping portionthat combine to define a handle of the expansion instrument and theexpansion grip illustrated in FIG. 6A;

FIG. 6C is a top plan view of the expansion instrument shown in FIG. 6B;

FIG. 6D is a detailed view of one of the gripping portions of theexpansion instrument shown in FIG. 6B;

FIG. 6E is an enlarged top plan view of the expansion grip shown in FIG.6B, coupled to the first and second arms of the frame shown in FIG. 3A,showing the expansion instrument actuated from a first position to asecond position, whereby the expansion grip applies an expansion forceto the first and second arms of the frame when the expansion instrumentis in the second position, the expansion force biasing the first andsecond arms of the frame to flex away from each other;

FIG. 7A is a perspective view of an intervertebral implant systemconstructed in accordance with another embodiment, the system includinga intervertebral implant frame, and an actuation instrument configuredas an expansion instrument that comprises a pair of clips that engagefirst and second arms of the frame along a direction that is similar toan insertion direction of the frame;

FIG. 7B is a top plan view of the intervertebral implant system shown inFIG. 7A;

FIG. 7C is an exploded view of the intervertebral implant system shownin FIG. 7A;

FIG. 8A is a perspective view of an intervertebral implant systemconstructed in accordance with another embodiment, the system includinga intervertebral implant frame and an actuation instrument configured asan expansion instrument that comprises a pair of clips that engage firstand second arms of the frame along a direction that is opposite to theinsertion direction of the frame;

FIG. 8B is a top plan view of the system shown in FIG. 8A;

FIG. 8C is an exploded view of the system shown in FIG. 8A;

FIG. 9A is a perspective view of an intervertebral implant frameconstructed in accordance with another embodiment, the frame including afirst arm, a second arm, and a respective expansion member that extendsout from and is integral to a respective arm of the frame;

FIG. 9B is a perspective view of an intervertebral implant frameconstructed in accordance with another embodiment, the frame including,a support member, a first arm, a second arm, and a respective expansionmember that extends out from and is integral to each arm of the frame,the expansion members extending proximate to the support member;

FIG. 10A is a perspective view of an intervertebral implant frameconstructed in accordance with another embodiment, the frame includingfirst and second arms that each include a crimp member configured to becrimped against the spacer body to thereby retain the spacer body to theframe;

FIG. 10B is a top plan view of the frame shown in FIG. 10A;

FIG. 11A is a perspective view of an intervertebral implant frameconstructed in accordance with another embodiment, the frame includingfirst and second arms that each include a pair of crimp membersconfigured to be crimped against the spacer body to thereby retain thespacer body to the frame;

FIG. 11B is a top plan view of the frame shown in FIG. 11A;

FIG. 12A is a perspective view of an intervertebral implant frameconstructed in accordance with another embodiment, the frame includingfirst and second arms that each include a crimp member configured as acrimp tab disposed within a window defined by the arm;

FIG. 12B is a top plan view of the frame shown in FIG. 12A;

FIG. 13A is a perspective view of an intervertebral implant frameconstructed in accordance with another embodiment, the frame includingfirst and second arms that each include at least one crimp memberconfigured as a crimp tab;

FIG. 13B is a top plan view of the frame shown in FIG. 13A;

FIG. 14A is a perspective view of an actuation instrument configured asa crimping instrument constructed in accordance with an embodiment, theinstrument including gripping members that are configured to crimp thecrimp members of the frames shown in FIGS. 10A and 11A;

FIG. 14B is a detailed top plan view of the gripping members of theinstrument shown in FIG. 14A, and an intervertebral implant disposedbetween the gripping members;

FIG. 14C is a top plan view of the gripping members illustrated in FIG.14B, shown in a crimped position, whereby the crimp members are crimpedonto a spacer body of the intervertebral implant so as to secure thearms to the intervertebral implant;

FIG. 14D is a detailed view of gripping members of a crimping instrumentconstructed in accordance with another embodiment, the gripping membersincluding a beaked protrusion configured to crimp the crimp members ofthe frame shown in FIG. 12A;

FIG. 15A is a perspective view of an intervertebral implant frameconstructed in accordance with another embodiment, the frame defining afour walled structure;

FIG. 15B is a top plan view of the frame shown in FIG. 15A;

FIG. 16A is a perspective view of a spacer body drill guide constructedin accordance with an embodiment, the drill guide including a clamp, anda cradle that is configured to mate with and support the clamp;

FIG. 16B is a perspective view of the clamp shown in FIG. 16A;

FIG. 16C is a perspective view of the clamp being mounted to the cradle;

FIG. 16D is a perspective view of the clamp after it has been mounted tothe cradle;

FIG. 16E is a perspective view of a drill bit being inserted into drillguide apertures defined by the clamp to thereby form clearance channelsin the spacer body;

FIG. 16F is a perspective view of a spacer body after the clearancechannels have been formed using the drill guide shown in FIG. 16A;

FIG. 17A is a perspective view of an intervertebral implant constructedin accordance with another embodiment, the intervertebral implant havingan intervertebral implant frame and a spacer body retained by theintervertebral implant frame;

FIG. 17B is a top plan view of the intervertebral implant shown in FIG.17A;

FIG. 17C is a perspective view of the intervertebral implant frame shownin FIG. 17A, the intervertebral implant frame having a support member, afirst arm extending from the support member, and a second arm extendingfrom the support member, the support member including tabs that arespaced from each other such that the frame provides a zero profile whenthe first and second arms are inserted into an intervertebral space;

FIG. 17D is a front elevation view of the intervertebral implant frameshown in FIG. 17C;

FIG. 17E is a top plan view of the intervertebral implant frame shown inFIG. 17C;

FIG. 17F is a side elevation view of the intervertebral implant frameshown in FIG. 17C;

FIG. 18A is a top plan view of the intervertebral implant inserted intoan intervertebral space defined between first and second vertebralbodies;

FIG. 18B is a front elevation view of the intervertebral implant shownin FIG. 18A; and

FIG. 18C is a side elevation view of the intervertebral implant shown inFIG. 18A.

DETAILED DESCRIPTION

Referring to FIGS. 1A and 1B, a superior vertebral body 10 a defines afirst or superior vertebral surface 14 a of an intervertebral space 18,and an adjacent second or inferior vertebral body 10 b defines aninferior vertebral surface 14 b of the intervertebral space 18. Thus,the intervertebral space 18 is disposed between or otherwise defined bythe vertebral bodies 10 a and 10 b. The vertebral bodies 10 a and 10 bcan be anatomically adjacent vertebral bodies, or can remain after aportion of bone has been removed. The intervertebral space 18 can bedisposed anywhere along the spine as desired, including at the lumbar,thoracic, and cervical regions of the spine. As illustrated, theintervertebral space 18 is illustrated after a discectomy, whereby thedisc material has been removed or at least partially removed to preparethe intervertebral space 18 to receive an intervertebral implant 22 thatcan achieve height restoration. As shown, the intervertebral implant 22can be affixed to the superior and inferior vertebral bodies 10 a and 10b with respective fixation elements 62. The intervertebral implant 22and the fixation elements 62 together define an intervertebral implantassembly 24.

Certain terminology is used in the following description for convenienceonly and is not limiting. The words “right”, “left”, “lower” and “upper”designate directions in the drawings to which reference is made. Thewords “inner” or “distal” and “outer” or “proximal” refer to directionstoward and away from, respectively, the geometric center of the implantand related parts thereof. The words, “anterior”, “posterior”,“superior,” “inferior,” “medial,” “lateral,” and related words and/orphrases are used to designate various positions and orientations in thehuman body to which reference is made and are not meant to be limiting.The terminology includes the above-listed words, derivatives thereof andwords of similar import.

The intervertebral implant 22 is described herein as extendinghorizontally along a longitudinal direction “L” and lateral direction“A”, and vertically along a transverse direction “T”. Unless otherwisespecified herein, the terms “lateral,” “longitudinal,” and “transverse”are used to describe the orthogonal directional components of variouscomponents. It should be appreciated that while the longitudinal andlateral directions are illustrated as extending along a horizontalplane, and that the transverse direction is illustrated as extendingalong a vertical plane, the planes that encompass the various directionsmay differ during use. For instance, when the intervertebral implant 22is implanted into the intervertebral space 18 along an insertiondirection I, the transverse direction T extends vertically generallyalong the superior-inferior (or caudal-cranial) direction, while thehorizontal plane defined by the longitudinal direction L and lateraldirection A lies generally in the anatomical plane defined by theanterior-posterior direction, and the medial-lateral direction,respectively. Accordingly, the directional terms “vertical” and“horizontal” are used to describe the intervertebral implant 22 and itscomponents as illustrated merely for the purposes of clarity andillustration.

As shown in FIGS. 1B and 1C, the vertebral surfaces 14 a and 14 b of thevertebral bodies 10 a and 10 b can define a geometrical centroid M thatis generally located at an anterior-posterior midpoint between ananterior end and a posterior end of the surfaces 14 a and 14 b. As shownin FIG. 1B, the intervertebral implant 22 is configured to be disposedor otherwise implanted in the intervertebral space 18 such that aportion of the intervertebral implant 22 is located on a posterior sideof a medial lateral plane that intersects the centroid M, and a portionof the intervertebral implant 22 is located on an anterior side of themedial lateral plane that intersects the centroid M. Such aconfiguration can ensure that the height restoration of theintervertebral space 18 remains relatively unchanged over time.

In reference to FIGS. 1A, 1B, 2A and 2B, the intervertebral implant 22includes an intervertebral implant frame 26 and a spacer body 30 that isretained by the frame 26. The intervertebral implant 22, defines aproximal end P and a distal end D. The frame 26 may be made from anybiocompatible material, such as TAN alloy, or PEEK. The spacer body 30may be composed of a synthetic material such as PEEK or a graftsubstitute such a tricalcium phosphate or hydroxyapatite. The spacerbody 30 may also be composed of a bone graft such as allograft bone,autograft bone or xenograft bone. By using a spacer body 30 composed ofbone graft, surface area for fusion can be maximized. Additionally,incorporation of a bone graft spacer body 30 promotes bony on-growth andincreased probability and speed of sound fusion. The frame 26 isconfigured to be attached to various bone graft spacer body footprintgeometries, which may or may not conform to the internal footprint ofthe frame 26.

As shown in FIGS. 3A-3E the frame 26 includes a support member 34, afirst arm 38 that extends from the support member 34, and a second arm42 that extends from the support member 34. In the illustratedembodiment, the first and second arms 38 and 42 are flexible arms thatextend from opposed ends of the support member 34 such that the supportmember 34, the first arm 38, and the second arm 42 together create athree wall structure that retains and secures the spacer body 30 to theframe 26.

As shown in FIGS. 3A-3C, the support member 34 includes a body 46 thatdefines an inner surface 50, an outer surface 54, and at least one, suchas two or such as four, fixation element receiving apertures 58 thatextend through the body 46 from the outer surface 54 to the innersurface 50. Each fixation element receiving aperture 58 is configured toreceive a respective fixation element, such as fixation element 62 shownin FIGS. 4A and 4B. While the fixation elements 62 are illustrated asscrews, it should be appreciated that the fixation elements 62 may alsobe nails or any other fixation element configured to attach theintervertebral implant 22 to the first and second vertebral bodies 10 aand 10 b. As shown, the support member 34 can further include at leastone, such as three tabs 64 that extend transversely from the body 46.The tabs 64 may sit on an anterior side of the vertebral bodies andprevent over-insertion of the frame 26 into the intervertebral space 18.In the illustrated embodiment, the support member 34 includes twosuperior tabs 64 and one inferior tab 64 that are each configured to sitflush or slightly proud of an anterior surface of the vertebral bodiesdepending on the patient's spinal anatomy and/or site preparation. Itshould be appreciated, however, that the support member 34 can includeother configurations for the tabs 64. For example, the support member 34can include a single superior tab 64 and two inferior tabs 64.

As shown in FIG. 3B, two of the fixation element receiving apertures 58are inner apertures 66 that extend through the body 46 at a downwardangle relative to the insertion direction I, and two of the fixationelement receiving apertures 58 are outer apertures 70 that extendthrough the body 46 at an upward angle relative to the insertiondirection I. The inner apertures 66 are configured to receive respectivefixation elements, such as fixation element 62 shown in FIGS. 4A and 4B,to thereby attach the intervertebral implant 22 to the inferiorvertebral body 10 b. Similarly, the outer apertures 70 are configured toreceive respective fixation elements 62 to thereby attach theintervertebral implant 22 to the superior vertebral body 10 a. It shouldbe appreciated, however, that the inner apertures 66 can extend throughthe body 46 at an upwards angle and the outer apertures 70 can extendthrough the body 46 at a downwards angle, as desired. Moreover, itshould be appreciated that the support member 34 can define any numberof fixation element receiving apertures 58 as desired.

As shown in FIG. 3B, the apertures 58 each define internal threads 78.The internal threads 78 are configured to engage external threads 80defined by a head 82 of the respective fixation element 62 that isreceived within the apertures 58. It should be appreciated, however,that the apertures 58 can be void of threads as desired. The orientationof the apertures 58 may be configured such that the fixation elementsthat are received by the apertures 58 may have an insertion variance of+/−5 degrees and do not allow toggling or settling. Once fully received,the fixation elements may lock to the frame 26 to thereby increase thesurgeon's reassurance of good screw trajectories and can act as a safetyby preventing possibilities of over-insertion during implantation.

As shown in FIG. 3C, support member 34 can include a retention member 73that extends from the inner surface 50. The retention member 73 isconfigured to help retain the spacer body 30 when the spacer body isbeing supported by the frame 26. The retention member 73 is illustratedas a spike though it should be appreciated, that the retention member 73can have other configurations. For example, the retention member 73 canbe configured as a blade.

As shown in FIGS. 2A, and 3A-3E, the first arm 38 and the second arm 42each extend from the support member 34 and define a first distalterminal end 83 and a second distal terminal end 84, respectively. Thefirst and second arms 38 and 42 each define gripping portions andsupport portions. The gripping portions are configured to retain thespacer body 30 while the support portions are configured to support thevertebral bodies 10 a and 10 b relative to each other. The grippingportions and the support portions can be a single structure or thesupport portions can be separate structures that extend from thegripping portions. The arms 38 and 42 can be radiolucent so as toincrease fluoroscopy visibility. The first arm 38 includes a first innerspacer contacting surface 88 and the second arm 42 includes a secondinner spacer contacting surface 92 that is spaced from the first innerspacer contacting surface 88 along a first direction, such as thelateral direction A. The inner surface of the support member 34, thefirst inner spacer contacting surface 88, and the second inner spacercontacting surface 92 together define a void 94 that is configured toreceive and grip the spacer body 30. The terminal ends 83 and 84 arespaced apart from the support member along a second direction, such asthe longitudinal direction L that is substantially perpendicular to thefirst direction so as to define first and second lengths L₁ and L₂,respectively of the first and second arms 38 and 42. The first andsecond arms 38 and 42 are sized such that the first and second lengthsL₁ and L₂ are each greater than a length L₃ defined between an anteriorend E of the inferior vertebral body 10 b and the centroid M of thesurface 14 b of the inferior vertebral body 10 b, as shown in FIG. 1C.It should be appreciated, that the first and second arms 38 and 42 canalso be sized such that the first and second lengths L₁ and L₂ aregreater than a length defined between an anterior end of the superiorvertebral body 10 a and a centroid of the surface 14 a of the superiorvertebral body 10 a. The first and second lengths L₁ and L₂ may bebetween about 3.5 mm and about 12 mm, between about 6.0 mm and about 10mm, and preferably about 9.5 mm. In some embodiments, the support member34, the first arm 38, and the second arm 42 extend around at least 51%of the spacer body 30, and preferably around at least 80% of the spacerbody 30.

The flexible arms 38 and 42 can have a transverse height and a lateralwidth that at least partially define a cross-sectional area of the arms38 and 42. The arms 38 and 42 can have a cross-sectional area that mayvary so long as the arms 38 and 42 are capable of elastically deformingor flexing to thereby allow the frame 26 to receive the spacer body andsubsequently apply a retention force to the spacer body 30 after theframe 26 has received the spacer body 30. In that regard, the arms 38and 42 are configured to elastically flex laterally outwardly away fromeach other, or otherwise elastically deform from a first position to asecond flexed position to allow the frame 26 to receive the spacer body30. It should be appreciated that the first position can be a relaxedposition of the arms 38 and 42 or a flexed position of the arms 38 and42 that is outwardly flexed with respect to a relaxed position. At leastrespective portions of the arms 38 and 42, such as contact locations 320and 324 (see FIG. 6E), are further spaced from each other in the secondposition than when in the first position. Once the spacer body 30 isdisposed between the arms 38 and 42, the arms 38 and 42 may flexinwardly toward each other to a third or engaged position whereby thearms 38 and 42 engage the spacer body 30 so as to secure the frame 26 tothe spacer body 30 as shown in FIG. 2. It should be appreciated that thethird position can be outwardly flexed with respect to the firstposition, and can be substantially equal to the first position. Thus,the respective portions of the arms 38 and 42 can be further spaced fromeach other when in the third position with respect to the firstposition, or the respective portions of the arms 38 and 42 can be spacedfrom each other when in the third position a distance substantiallyequal to the distance that the respective portions of the arms 38 and 42are spaced when in the first position. Thus, it can be said that whenthe arms 38 and 42 are in the third position, at least respectiveportions of the arms 38 and 42 are spaced apart a distance equal to orgreater than (or no less than) the distance that the arms 38 and 42 arespaced when in the first position. It will be further appreciated fromthe description below in accordance with certain embodiments (see, forinstance FIG. 14C) that at least respective portions of the arms 38 and42 can be spaced apart a distance when in the engaged position that isless than the distance that the respective portions of the arms 38 and42 are spaced apart when in the first position.

As shown in FIG. 3C, the first and second arms 38 and 42 extend from thesupport member 34 such that the first and second arms 38 and 42 areangled toward each other so as to push the spacer body 30 toward theother of the first and second arms 38 and 42 and toward the supportmember 34. For example, the inner surface of the support member 34 andthe first inner spacer contacting surface 88 form an angle Θ₁ that isless than 90 degrees, and the inner surface 50 of the support member 34and the second inner spacer contacting surface 92 form an angle Θ₂ thatis less than 90 degrees. In the illustrated embodiment, Θ₁ and Θ₂ areeach about 88 degrees, though it should be appreciated that Θ₁ and Θ₂may be any angle as desired, and may be different angles with respect toeach other.

As shown in FIGS. 3C and 3D, each arm 38 and 42 includes a substantiallystraight portion 100 that extends from the support member 34, and adistal bent or angled portion 104 that extends from a distal end of thestraight portion 100 toward the other of the bent portions 104 such thatthe bent portions 104 are configured to contact a distal surface of thespacer body 30. As shown, the bent portions 104 at least partially wraparound the spacer body 30 to thereby prevent the spacer body 30 fromseparating from the frame 26 after the spacer body 30 has been retainedby the frame 26. As shown in FIG. 3A, each arm 38 and 42 can include atleast one, such as a plurality of retention members 116 that extend outfrom the first and second inner spacer contacting surfaces 88 and 92. Inthe illustrated embodiment, the retention members 116 define teeth thatextend out of the bent portions 104 so as to form a column of teeth oneach bent portion 104. The retention members 116 are configured toengage the spacer body 30 when the frame 22 is retaining the spacer body30 to thereby ensure that the spacer body 30 remains retained by theframe 22. It should be appreciated, however, that the retention member116 can have any configuration as desired, so long as the retentionmember 116 is capable of engaging the spacer body 30. For example, theretention members 116 can be spikes that extend from the inner surfaces88 and 92 at an angle, elongate blades, or even punches that can bepunched into the spacer body 30 by an individual after the spacer body30 is disposed in the frame 26.

As shown in FIG. 3D, the arms 38 and 42 may be configured to assist inbearing compressive loads by the vertebral bodies 10 a and 10 b tothereby mitigate subsidence and settling. As shown, each arm 38 and 42defines a respective distal portion 110 and a respective proximalportion 114. The distal portions 110 are spaced apart from the proximalportions 114 along the longitudinal direction L such that when the frame26 is disposed in the intervertebral space 18, the distal portions 110are on the posterior side of the centroid M of the surface 14 b of theinferior vertebral body 10 b, and the proximal portions 114 are on theanterior side of the centroid M of the surface 14 b of the inferiorvertebral body 10 b. Each distal portion 110 defines a superiorvertebral body contacting surface 118 and an inferior vertebral bodycontacting surface 122. Similarly, each proximal portion 114 defines asuperior vertebral body contacting surface 126 and an inferior vertebralbody contacting surface 130. Because of the length of the arms 38 and 42and because of the transverse height of the arms 38 and 42 at theirdistal and proximal portions, the frame 26 can bear compressive loadsfrom the vertebral bodies if the spacer body 30 were to subside.

As shown in FIG. 3D, the arms 38 and 42 may be configured to conform tothe lordotic curve of the spine and in particular of the intervertebralspace 18 in which the frame 26 is to be disposed. For example, a linedrawn between the superior vertebral body contacting surfaces 118 and126 of the first arm 38 forms an angle that is between about 0 degreesand about −5 degrees with respect to the insertion direction I, and aline drawn between the inferior vertebral body contacting surfaces 122and 130 of the first arm forms a line that is between about 0 degreesand about 5 degrees with respect to the insertion direction I.Similarly, a line drawn between the superior vertebral body contactingsurfaces 118 and 126 of the second arm 42 forms an angle that is betweenabout 0 degrees and about −5 degrees with respect to the insertiondirection, and a line drawn between the inferior vertebral bodycontacting surfaces 122 and 130 of the second arm 42 forms an angle thatis between about 0 degrees and about 5 degrees with respect to theinsertion direction I. It should be appreciated, however, that the linesdrawn between the superior vertebral body contacting surfaces 118 and126, and between the inferior vertebral body contacting surfaces 122 and130 can be any angle as desired. For example, the lines may be parallelto each other. Therefore, it can be said that a first plane is definedby the superior vertebral body contacting surfaces, and a second planeis defined by the inferior vertebral body contacting surfaces. The firstplane and the second plane can be parallel to each other or convergetoward each other.

As shown in FIG. 3D, each arm 38 and 42 further includes a superiorcut-out 140 and an inferior cut-out 144 to thereby provide visual accessto the superior vertebral body 10 a and to the inferior vertebral body10 b respectively when the frame 26 is disposed in the intervertebralspace 18. The cut-outs 140 and 144 are each disposed between theproximal portions 114 and distal portions 110 of the first and secondarms 38 and 42. As shown, the superior cut-outs 140 extend laterallythrough an upper portion of the arms 38 and 42 so as to define uppercurved recesses 148 in the straight portions 100 of the arms 38 and 42.Similarly, the inferior cut-outs 144 extend laterally through a lowerportion of the arms 38 and 42 so as to define lower curved recesses 152in the arms 38 and 42. It should be appreciated that the superior andinferior cut-outs 140 and 144 can have other configurations as desired.For example, the cut-outs 140 and 144 can define rectangular channelsthat extend through the arms 38 and 42.

As shown in FIGS. 3D and 3E, each arm 38 and 42 can further include awindow 156 that extends laterally through the straight portions 100 ofthe arms 38 and 42 between the superior and inferior cut-outs 140 and144. The windows 156 are configured to provide visual access to thespacer body 30 through the first and second arms 38 and 42 when theframe 26 is retaining the spacer body 30. As shown, the windows 156 areoval shaped and elongate along the longitudinal direction L. It shouldbe appreciated, however, that the windows 156 can have any shape asdesired. For example, the windows 156 can also be rectangular shaped.

As shown in FIGS. 3A, 3D, and 3E, each arm 38 and 42 includes anengagement member 170 that is configured to receive a first and a secondexternal expansion force, respectively, from an expansion instrumentprior to insertion of the spacer body 30 into the void 94 such that atleast one of the first and second arms 38 and 42 elastically expands orelastically flexes with respect to the other of the first and secondarms 38 and 42 in response to the expansion forces. As shown in FIG. 3A,the engagement members 170 each define a dove-tailed slot 174 thatdefines an opening 178 at its distal end such that the expansioninstrument can engage the dove-tailed slot 174 in a direction that isopposite to the insertion direction I of the frame 26. As shown in FIG.3D, the dove-tailed slots 174 are wider at the openings 178 and taper asthey extend proximally. The wider openings 178 provide a guide for theexpansion instrument to engage the engagement members 170. As shown inFIG. 3A, the dove-tailed slots 174 each include a pair of opposedrecesses 182 that define angled engagement surfaces 186. It should beappreciated, however, that the engagement members 170 can have anyconfiguration as desired so long as they can receive respectiveexpansion forces.

Now referring to FIG. 5A, the spacer body 30 that is received within theframe 26 is preferably made from a bone graft material such as allograftbone, autograft bone, or xenograft bone, for example. As shown in FIG.5A, the spacer body 30 can include cancellous bone 190 that is at leastpartially surrounded by cortical bone 194. It should be appreciated,however, that the spacer body 30 can be made from only cancellous bone190 or from only cortical bone 194.

As shown in FIGS. 5B-5D, the spacer body can alternatively be made froma synthetic material. Referring to FIGS. 5B-5D, the spacer body 30 issized and dimensioned to fit within the frame 26. Though not required,the spacer body may have a lateral width of between about 10 mm andabout 16 mm, a longitudinal length of between about 10 mm and 17 mm, anda transverse height that is between about 5 mm and about 12 mm. Theouter footprint of the spacer body 30 can vary and the frame 26 maystill be able to retain the spacer body 30. That is, the frame 26 or atleast the arms 38 and 42 are configured to retain a first spacer body 30having a first maximum width, a first outer footprint, or a firstcross-sectional dimension, and a second spacer body having a secondmaximum width, a second outer footprint, or a second cross-sectionaldimension that is different than those of the first spacer body 30.Therefore, the frame 26 and in particular the arms 38 and 42 can retainspacer bodies 30 that are made from bone shaped by the surgeon and notjust spacer bodies 30 that are machined to have specific dimensionsprior to insertion into the frame 26.

As shown in FIGS. 5B-5D, the spacer body 30 can define a superior orupper or outer bone engaging surface 200 and an opposed inferior orlower or outer bone engaging surface 204. The surfaces 200 and 204 areconfigured to engage the superior and inferior surfaces 14 a and 14 b,respectively of the vertebral bodies 10 a and 10 b. The spacer body 30can further define side surfaces 208 that are configured to be engagedby the first and second inner spacer contacting surfaces of the firstand second arms 38 and 42 to thereby retain the spacer body 30 withinthe frame 26.

As shown in FIGS. 6A-6E, the spacer body 30 can be coupled to the frame26 using an actuation instrument 210 that is configured as an expansioninstrument. The instrument 210, the frame 26, and in some cases thespacer body 30 can together define an intervertebral implant system 214.The expansion instrument 210 includes a grip 212 and a handle 213. Thegrip 212 is configured as an expansion grip and is configured to applythe first and second expansion forces to the engagement members 170 ofthe first and second arms 38 and 42. The first and second expansionforces will elastically expand the first and second arms 38 and 42 ofthe frame 26 to thereby allow the spacer body 30 to be received by thevoid 94 of the frame 26.

As shown, the instrument 210 includes a first arm 220 that is configuredto releasably couple to the first arm 38 of the frame 26, and a secondarm 224 that is rotatably coupled to the first arm 220 at a first pivot228 and is configured to releasably couple to the second arm 42 of theframe 26. The first and second arms 220 and 224 are configured asexpansions arms. The first and second expansion arms 220 and 224 arepivotally coupled to each other at the first pivot 228 such thatrotation of the first and second expansion arms 220 and 224 about thefirst pivot 228 causes the first and second arms 38 and 42 of the frame26 to elastically flex away from each other when the instrument 210 iscoupled to the frame 26. Therefore, the instrument 210 is configured tohave a first position or configuration whereby the instrument 210 can becoupled to the frame 26, and a second position or configuration wherebythe instrument 210 is applying expansion forces to the arms 38 and 42 ofthe frame 26 so that the frame can receive the spacer body 30.

As shown in FIGS. 6B and 6C, each expansion arm 220 and 224 includes ahandle portion 232 that extends proximally from the first pivot 228 anda gripping portion 236 that extends distally from the first pivot 228.The handle portions 232 define the handle 213, and the gripping portions236 define the grip 212. The handle portions 232 are configured to begripped by an individual such that the handle portions 232 can besqueezed or otherwise moved toward each other. The expansion instrument210 can further include a handle locking mechanism 240 that isconfigured to lock the handle portions 232 relative to each other afterthe handle portions 232 have been moved toward each other. In theillustrated embodiment, the locking mechanism 240 includes a threadedshaft 244 and a nut 248. As at least one of the handle portions 232 ismoved along the shaft 244, the nut 248 can be threaded along the shaft244 to thereby lock the handle portions 232 relative to each other. Itshould be appreciated, however, that the locking mechanism 240 caninclude other configurations, as desired. For example, the lockingmechanism 240 can have a ratchet configuration.

As shown in FIGS. 6C and 6D, the gripping portions 236 are configured toexpand the frame arms as the handle portions 232 are moved toward eachother. Each gripping portion 236 includes an extension member 250 thatextends distally from the first pivot 228, and a gripping member 254that is pivotally coupled to a distal end of the extension member 250 ata second pivot 258. Each gripping member 254 includes an engagementmember 262 that is configured to engage respective engagement members170 of the first and second arms 38 and 42 of the frame 26. As shown inFIG. 6D, the engagement members 262 are dove-tailed members 266 that areopposed to each other and are configured to mate with the dove-tailedslots of the first and second arms 38 and 42 to thereby couple theexpansion instrument 210 to the frame 26. As shown, each dove-tailedmember 266 includes a pair of transversely opposed protrusions 280 thateach define an angled engagement surface 284 that is configured to abutor otherwise contact a respective angled engagement surface 186 of theslots 174 when the engagement members 262 are mated with the engagementmembers 170. It should be appreciated that the engagement members 262can have other configurations as desired. For example, the engagementmembers 262 and the engagement members 170 can be reversed.

As shown in FIG. 6D, a proximal end of each engagement member 262defines a tapered lead-in portion 270 that allows the engagement members262 to easily be guided into the openings 178 of the engagement members170. Therefore, the expansion instrument 210 can easily be coupled tothe frame 26 along a direction that is opposite the insertion directionI. That is, if the frame 26 is stationary, the expansion instrument 210can be coupled to the frame 26 by translating the instrument 210 along adirection that is opposite the insertion direction I.

As shown in FIG. 6C, each gripping member 254 includes a pair of stops300 that extend proximally toward the extension member 250 and arespaced apart from the extension member 250. As the gripping member 254rotates about the second pivot 258 the stops 300 will limit the rotationby contacting the extension member 250. Therefore, the angular range inwhich the gripping members 254 can rotate about the second pivots 258will depend on the distance in which the stops 300 are spaced apart fromthe extension members 250.

As shown in FIG. 6C, each gripping portion 236 further includes abiasing member 304 that is configured to bias the gripping members 254toward each other. In the illustrated embodiment, the biasing members304 are leaf springs 308 that are coupled to the extension members 250and urge against an outer surface of the gripping members 304. Bybiasing the gripping members 254 toward each other, the expansioninstrument 210 can more easily and more predictably be coupled to theframe 26. It should be appreciated, however, that the biasing members304 can have other configurations as desired. For example, the biasingmembers can be elastically flexible wires and can be disposed within thegripping members 254 as desired.

In operation and in reference to FIG. 6E, the expansion instrument 210is coupled to the frame 26 by placing the engagement members 262 of theinstrument 210 distal to the engagement members 170 of the frame 26. Bytranslating or otherwise moving the frame 26 or the instrument 210toward the other, the engagement members 262 will engage the engagementmembers 170 to thereby couple the frame 26 to the instrument 210 suchthat the second pivots 258 of the instrument 210 abut an outer surfaceof the flexible arms 38 and 42 proximate to the support member 34. Bysqueezing the handle portions 232 toward each other, the extensionmember 250 of the first expansion arm 220 will rotate counterclockwiseabout the first pivot 228 and the gripping member 254 of the firstexpansion arm 220 will rotate clockwise about the second pivot 258.Conversely, the extension member 250 of the second expansion arm 224will rotate clockwise about the first pivot 228 and the gripping member254 of the second expansion arm 224 will rotate counterclockwise aboutthe second pivot 258.

This rotation will cause at least one of the first and second arms 38and 42 to elastically flex away from the other. For example, the firstand second inner spacer contacting surfaces 88 and 92 of the first andsecond arms 38 and 42 can define respective first and second respectivecontact locations 320 and 324, and at least one of the first and secondarms 38 and 42 is flexible so as to be movable between a first position,whereby the frame 26 defines a first distance d₁ that extends along thelateral direction A between the first and second contact locations 320and 324, and a second position, whereby the frame 26 defines a seconddistance d₂ that extends along the lateral direction A between the firstand second contact locations 320 and 324. It should be appreciated thatthe first and second contact locations 320 and 324 can be locatedanywhere along the arms 320 and 324 so long as they remain the same whenthe first and second distances are measured.

As shown in FIG. 6E, the second distance d₂ is greater than the firstdistance d₁ such that when in the second position, the void 94 defines across-sectional dimension that is greater than that of the spacer body30 such that the void 94 is sized to receive the spacer body 30. Whilethe arms 38 and 42 are elastically flexed, at least one of the arms 38and 42 is biased toward the first position. Therefore, when the handleportions 232 of the instrument 210 are released, the arms 38 and 42 willflex back to a third position, and when in the third position, the frame26 defines a third distance d₃ that extends along the lateral directionA between the first and second contact locations 320 and 324 and is lessthan the second distance d₂ (See FIG. 2B). When in the third position atleast one of the first and second inner contacting surfaces 88 and 92 ofthe arms 38 and 42 will apply a retention force against the spacer body30 along a direction toward the other of the first and second innerspacer contacting surfaces 88 and 92.

In another embodiment and in reference to FIGS. 7A-7C, an intervertebralimplant system 350 can include an intervertebral implant frame 426, andan actuation instrument 428 that is also configured as an expansioninstrument. The frame 426 includes a support member 434, a first arm 438that extends from the support member 434, and a second arm 442 thatextends from the support member 434. The first and second arms 438 and442 are flexible arms and are configured to elastically flex away fromeach other so that the frame 426 can receive a spacer body 30. Thesupport member 434, the first arm 438, and the second arm 442 aresimilar to the support member 34, the first arm 38, and the second arm42 shown in FIG. 3A, and include like structure unless otherwisedescribed.

As shown in FIG. 7C, each of the first and second arms 438 and 442includes a straight portion 446 and a bent portion 450 that extends froma distal end of the straight portion 446 at angle toward the other ofthe bent portions 450. Each arm 438 and 442 further includes anengagement member 454 that defines a slot 458 that extends through therespective arm 438 and 442. As shown the slots 458 extend through thestraight portions 446 at substantially the same angle in which the bentportions 450 extend from the distal end of the straight portions 446.Moreover, the slots 458 extend through the straight portions 446 andinto a cavity 460 defined by the bent portions 450. Each bent portion450 further includes a retention bump 461. The bumps 461 are configuredto provide a tactile feedback indicating that the expansion instrument428 is coupled to the arms 438 and 442.

As shown in FIGS. 7A-7C, the expansion instrument 428 can include a pairof removable clips 470 that are configured to engage the slots 458defined by the arms 438 and 442 by translating the clips 470 distally oralong a direction that has a directional component that is the same asthe insertion direction I. As shown, each clip 470 can be asubstantially straight elongate member 474 having an engagement member476 that is defined by a pair of elongate cantilevered beams 478 at itsdistal end that are separated by a recess 482. An outer beam 478 caninclude a recess 479 that is configured to receive the retention bump461 and provide an indication that the clips 470 are properly coupled tothe arms 438 and 442. As shown in FIG. 7B, each clip 470 can be attachedto a respective arm 438 and 442 by inserting one of the cantileveredbeams 478 of a respective clip 470 into a slot 458 of the respectivearms 438 and 442. The cantilevered beam 478 that is inserted into theslot 458 will be received by the cavity 460 defined by the bent portion450.

Once coupled to the arms 438 and 442, the clips 470 extend out from thearms 438 and 442 at an angle such that the clips 470 diverge from eachother as they extend proximally. By squeezing a proximal portion of theclips 470 toward each other, the cantilevered beams 478 apply anexpansion force to the engagement members 454 or at least to the bentportions 450 such that the arms 438 and 442 elastically flex away fromeach other. While flexed, the frame 426 can receive the spacer body 30.By releasing the clips 470, the arms 438 and 442 will apply a retentionforce to the spacer body 30 to thereby retain the spacer body 30 in theframe 426.

In another embodiment and in reference to FIGS. 8A-8C, an intervertebralimplant system 522 can include an intervertebral implant frame 526, andan actuation instrument 528 that is configured as an expansioninstrument. The frame 526 includes a support member 534, a first arm 538that extends from the support member 534, and a second arm 542 thatextends from the support member 534. The first and second arms 538 and542 flexible arms and are configured to elastically flex away from eachother so that the frame 526 can receive a spacer body 30. The supportmember 534, the first arm 538, and the second arm 542 are similar to thesupport member 34, the first arm 38, and the second arm 42 shown in FIG.3A, and include like structure unless otherwise described.

As shown in FIG. 8C, each of the first and second arms 538 and 542includes a straight portion 546 and a bent portion 550 that extends froma distal end of the straight portion 546 at angle toward the other ofthe bent portions 550. Each arm 538 and 542 further includes anengagement member 554 that defines a slot 558 that extends through therespective arm 538 and 542. As shown the slots 558 extend through thebent portions 550 along a direction that is opposite the insertiondirection I. Moreover, the slots 558 extend into a cavity 560 that isdefined by each straight portion 546. Each straight portion 546 furtherincludes a retention bump 561. The bumps 561 are configured to provide atactile feedback indicating that the expansion instrument 528 is coupledto the arms 538 and 542.

As shown in FIGS. 8A-8C, the expansion instrument 528 can include a pairof removable clips 570 that are configured to engage the slots 558defined by the arms 538 and 542 by translating the clips 570 proximallyor along a direction that is opposite to the insertion direction I. Asshown, each clip 570 includes a handle portion 574 and a grippingportion 578 that extends distally from the handle portion 574. Eachgripping portion 578 includes a body 582 and an engagement member 584that extends out from the body 582. As shown, each engagement member 584defines a proximally extending protrusion 586 that is spaced from the582 such that a recess 588 is defined between the protrusion 586 andbody 582. Each gripping portion 578 further includes a shoulder 590 thatextends out from the body 582 and is configured to abut the arms 538 and542 proximate to the support member 526 when the clip 570 is coupled tothe frame 526. Each clip 570 further includes a recess 579 that isconfigured to receive the retention bump 561 and provide an indicationthat the clips 570 are properly coupled to the arms 538 and 542. Asshown in FIG. 8B, each clip 570 can be attached to a respective arm 538and 542 by inserting the protrusion 586 of a respective clip 470 into aslot 558 of a respective arm 538 and 542. The protrusion 586 will bereceived by the cavity 560 defined by the straight portion 546.

Once coupled to the arms 538 and 542, the clips 570 extend out from thearms 538 and 542 such that the handle portions 574 are proximal to thefront of the frame 526 and the shoulders 590 are abutting the arms 538and 542 proximate to the support member 526 as shown in FIG. 8B. Bysqueezing the handle portions 574 toward each other, clips 570 rotateabout the shoulders 590 and the protrusions 586 apply an expansion forceto the engagement members 554 or to at least the straight portions 546such that the arms 538 and 542 elastically flex away from each other.While flexed, the frame 526 can receive the spacer body 30. By releasingthe clips 570, the arms 538 and 542 will apply a retention force to thespacer body 30 to thereby retain the spacer body 30 in the frame 526.

It should be appreciated that the engagement members of the frames 26,426, and 526, and the engagement members of the instruments 210, 428,and 528 are interchangeable. Therefore, for example, frame 26 andinstrument 210 can include any of the engagement members 170, 262, 454,476, 554, and 584 so long as the engagement members of the frame 26 canmate with the engagement members of the instrument 210 to therebyreleasably couple the frame 26 to the instrument 210.

As shown in FIGS. 9A and 9B, the actuation instrument can beincorporated into the frame such that the actuation instrument and theframe are a unitary part. In accordance with another embodiment and inreference to FIG. 9A, an intervertebral implant frame 626 can include asupport member 634, a first arm 638 that extends from the support member634, and a second arm 642 that extends from the support member 634. Thefirst and second arms 638 and 642 are flexible arms and are configuredto elastically flex away from each other so that the frame 626 canreceive a spacer body 30. The support member 634, the first arm 638, andthe second arm 642 are similar to the support member 34, the first arm38, and the second arm 42 shown in FIG. 3A, and include like structureunless otherwise described.

As shown in FIG. 9A, each of the first and second arms 638 and 642includes a straight portion 646 and a bent portion 650 that extends froma distal end of the straight portion 646 at angle toward the other ofthe bent portions 650. Each arm 638 and 642 further includes anexpansion member 654 that extends out from the arm at angle. As shown,each expansion member 654 extends out from the proximal end of the bentportion 650 and includes a handle portion 660 that is spaced apart fromthe straight portion 646. By squeezing the handle portions 660 towardeach other, the arms 638 and 642 will elastically flex away from eachother so that the frame 626 can receive the spacer body 30. As shown inFIG. 9B, the expansion members 654 can extend proximally such thathandle portions 660 are proximal to the arms 638 and 642 to therebyprovide more lavage. Once the frame 626 has been coupled to the spacerbody 30, the expansion members 654 can be broken off and removed fromthe frame 626.

In another embodiment the frame can be configured to have portions ofthe frame arms crimped toward the spacer body to thereby retain thespacer body. In such embodiments, the frame is capable of receiving thespacer body without flexing the arms of the frame away from each other.The spacer body will then be retained by the frame by crimping the armstoward the spacer body to thereby provide a retention force to thespacer body.

For example, in reference to FIGS. 10A and 10B, an intervertebralimplant frame 726 includes a support member 734, a first arm 738 thatextends from the support member 734, and a second arm 742 that extendsfrom the support member 734. The first and second arms 734 and 738 arecrimpable arms such that the frame 726 is configured to have a firstinitial position in which the spacer body 30 can be disposed between thearms 738 and 742, and a second crimped or engaged position in which thearms 738 and 742 are crimped toward each other to thereby apply aretention force to the spacer body 30. The support member 734, the firstarm 738, and the second arm 742 are similar to the support member 34,the first arm 38, and the second arm 42 shown in FIG. 3A, and includelike structure unless otherwise described.

The first and second arms 738 and 742 are configured to be crimpedrather than flexed. As shown, the arms 738 and 742 include first andsecond inner spacer contacting surfaces 744 and 746, respectively thatare configured to contact and retain the spacer body 30. That is, theinner surface of the support member 734, the first inner spacercontacting surface 744 and the second inner spacer contacting surface746 together define a void 748 that is configured to receive the spacerbody 30. Each arm 738 and 742 further includes a substantially straightportion 750 and a crimp member 752 that extends distally from thestraight portion 748. As shown, the crimp members 752 are each coupledto the straight portions 750 by a hinge 756. In the illustratedembodiment, the hinges 756 define transverse bending grooves 758 formedin the inner spacer contacting surfaces 744 and 746.

In operation, the frame 726 can receive the spacer body 30 within thevoid 748 without expanding the arms 738 and 742 away from each other.Though it should be appreciated some expanding may occur. Once thespacer body 30 is properly positioned, the first crimp member 752 of thefirst arm 738 can be rotated about the first hinge 756 such that thefirst crimp member 752 is bent toward the second arm 742. Similarly, thesecond crimp member 752 of the second arm 742 can be rotated about thesecond hinge 756 such that the second crimp member 752 is bent towardthe first arm 738. After the crimp members 752 have been crimped orotherwise bent, the arms 738 and 742 apply a retention force to thespacer body 30 to thereby retain the spacer body 30 to the frame 726. Asshown, each arm 738 and 742 can further include a retention member 760that extends from the first and second inner spacer contacting surfaces744 and 746, respectively. The retention members 760 are configured toengage the spacer body 30 to thereby prevent migration of the spacerbody 30 from the frame 726.

In another embodiment and in reference to FIGS. 11A and 11B, anintervertebral implant frame 826 can include more than two crimpmembers. As shown, the frame 826 includes a support member 834, a firstarm 838 that extends from the support member 834, and a second arm 842that extends from the support member 834. The first and second arms 838and 842 are crimpable arms such that the frame 826 is configured to havea first initial position in which the spacer body 30 can be disposedbetween the arms 838 and 842, and a second crimped or engaged positionin which the arms 838 and 842 are crimped toward each other to therebyapply a retention force to the spacer body 30. The support member 834,the first arm 838, and the second arm 842 are similar to the supportmember 34, the first arm 38, and the second arm 42 shown in FIG. 3A, andinclude like structure unless otherwise described.

The first and second arms 838 and 842 are configured to be crimpedrather than flexed. As shown, the arms 838 and 842 include first andsecond inner spacer contacting surfaces 844 and 846, respectively thatare configured to contact and retain the spacer body 30. That is, theinner surface of the support member 834, the first inner spacercontacting surface 844 and the second inner spacer contacting surface846 together define a void 848 that is configured to receive the spacerbody 30. Each arm 838 and 842 further includes a first crimp member 850and a second crimp member 852 that extends distally from the first crimpmember 850. In other words, the first arm 838 can include a first crimpmember 850 and a third crimp member 852 of the frame 826, and the secondarm 842 can include a second crimp member 850 and a fourth crimp member852 of the frame 826. As shown, the first crimp member 850 and thesecond crimp member 850 are each coupled to the support member 834 byfirst and second hinges 856 respectively. Similarly, the third andfourth crimp members 852 are coupled to the first crimp members 850 bythird and fourth hinges 860 respectively. In the illustrated embodiment,the hinges 856 and 860 define transverse bending grooves 864 formed inthe outer surfaces of the first and second arms 838 and 842.

In operation, the frame 826 can receive the spacer body 30 within thevoid 848 without expanding the arms 838 and 842 away from each other.Though it should be appreciated some expanding may occur. Once thespacer body 30 is properly positioned, the first crimp member 850 andthe second crimp member 852 of the first arm 838 can be rotated aboutthe first and second hinges 856 and 860 respectively such that the crimpmembers 850 and 852 are bent toward the second arm 842. Similarly, thefirst crimp member 850 and the second crimp member 852 of the second arm842 can be rotated about the first and second hinges 856 and 860respectively such that the crimp members 850 and 852 are bent toward thefirst arm 838. After the crimp members 850 and 852 have been bent, thearms 838 and 842 apply a retention force to the spacer body 30 tothereby retain the spacer body 30 to the frame 826. As shown, each arm838 and 842 can further include a retention member 868 that extends fromthe first and second inner spacer contacting surfaces 844 and 846,respectively. The retention members 868 are configured to engage thespacer body 30 to thereby prevent migration of the spacer body 30 fromthe frame 826.

In another embodiment and in reference to FIGS. 12A and 12B, anintervertebral implant frame 926 can include crimp members that definecrimping tabs. As shown, the frame 926 includes a support member 934, afirst arm 938 that extends from the support member 934, and a second arm942 that extends from the support member 934. The first and second arms938 and 942 are crimpable arms such that the frame 926 is configured tohave a first initial position in which the spacer body 30 can bedisposed between the arms 938 and 942, and a second crimped or engagedposition in which the arms 938 and 942 are crimped toward each other tothereby apply a retention force to the spacer body 30. The supportmember 934, the first arm 938, and the second arm 942 are similar to thesupport member 34, the first arm 38, and the second arm 42 shown in FIG.3A, and include like structure unless otherwise described.

The first and second arms 938 and 942 are configured to be crimpedrather than flexed. As shown, the arms 938 and 942 include first andsecond inner spacer contacting surfaces 944 and 946, respectively thatare configured to contact and retain the spacer body 30. That is, theinner surface of the support member 934, the first inner spacercontacting surface 944 and the second inner spacer contacting surface946 together define a void 948 that is configured to receive the spacerbody 30. Each arm 938 and 942 further includes a substantially straightportion 950, a bent portion 951 extending from a distal end of thestraight portion 950, and a crimp member 952 that is formed in thestraight and bent portion 950 and 951. As shown, the crimp members 952each define a crimping tab 956 that is attached to one of the straightportion 950 or the bent portion 951 by a hinge 958. In the illustratedembodiment, a proximal edge of the crimping tab 956 is coupled to thestraight portion 950 and defines the hinge 958. It should beappreciated, however, that an upper edge, a lower edge, or a distal edgeof the crimping tabs 956 could define the hinges 958. As shown, eachcrimping tab 956 is disposed within a window defined by the respectivearm.

In operation, the frame 926 can receive the spacer body 30 within thevoid 948 without expanding the arms 938 and 942 away from each other.Though it should be appreciated some expanding may occur. Once thespacer body 30 is properly positioned, the crimping tab 956 of the firstarm 938 can be rotated about the hinge 958 such that the crimping tab956 is bent toward the second arm 942. Similarly, the crimping tab 956of the second arm 942 can be rotated about the hinge 958 such that thecrimping tab 956 is bent toward the first arm 938. After the crimpingtabs 956 have been bent, the frame is in the crimped or engaged positionsuch that the arms 938 and 942 apply a retention force to the spacerbody 30 to thereby retain the spacer body 30 to the frame 926. It shouldbe appreciated that the first and second arms 938 and 942 can includeany number of crimping tabs 956 as desired.

In another embodiment and in reference to FIGS. 13A and 13B, anintervertebral implant frame 1026 can include crimp members that definetabs disposed along upper and lower edges of the arms. As shown, theframe 1026 includes a support member 1034, a first arm 1038 that extendsfrom the support member 1034, and a second arm 1042 that extends fromthe support member 1034. The first and second arms 1034 and 1038 arecrimpable arms such that the frame 1026 is configured to have a firstinitial position in which the spacer body 30 can be disposed between thearms 1038 and 1042, and a second crimped or engaged position in whichthe arms 1038 and 1042 are crimped toward each other to thereby apply aretention force to the spacer body 30. The support member 1034, thefirst arm 1038, and the second arm 1042 are similar to the supportmember 34, the first arm 38, and the second arm 42 shown in FIG. 3A, andinclude like structure unless otherwise described.

The first and second arms 1038 and 1042 are configured to be crimpedrather than flexed. As shown, the arms 1038 and 1042 include first andsecond inner spacer contacting surfaces 1044 and 1046, respectively thatare configured to contact and retain the spacer body 30. That is, theinner surface of the support member 1034, the first inner spacercontacting surface 1044 and the second inner spacer contacting surface1046 together define a void 1048 that is configured to receive thespacer body 30. Each arm 1038 and 1042 further includes a substantiallystraight portion 1050, a bent portion 1051 extending from a distal endof the straight portion 1050, and at least one, such as a plurality ofcrimp members 1052 that are formed in upper and lower edges of the arms1038 and 1042. As shown, the crimp members 1052 each define a crimpingtab 1056 that are each attached to the straight and bent portions 1050and 1051 by respective horizontal hinges 1058.

In operation, the frame 1026 can receive the spacer body 30 within thevoid 1048 without expanding the arms 1038 and 1042 away from each other.Though it should be appreciated some expanding may occur. Once thespacer body 30 is properly positioned, the crimping tabs 1056 of thefirst arm 1038 can be rotated about the hinges 1058 such that thecrimping tabs 1056 are bent toward the second arm 1042. Similarly, thecrimping tabs 1056 of the second arm 1042 can be rotated about thehinges 1058 such that the crimping tabs 1056 are bent toward the firstarm 1038. After the crimping tabs 1056 have been bent, the frame 1026 isin the crimped or engaged position such that the arms 1038 and 1042apply a retention force to the spacer body 30 to thereby retain thespacer body 30 to the frame 1026. It should be appreciated that thefirst and second arms 1038 and 1042 can include any number of crimpingtabs 1056 as desired.

As shown in FIGS. 14A-14C, the spacer body 30 can be coupled to theframe 726 using an actuation instrument 1110 that is configured as acrimping instrument. The instrument 1110 and the frame 726 can togetherdefine an intervertebral implant system 1114. The crimping instrument1110 includes an actuation grip 1116 that is configured as a crimpinggrip so as to apply a crimping force to the frame 726. For instance, inaccordance with the illustrated embodiment, the crimping grip 1116 isconfigured to apply first and second crimping forces to the crimpmembers 752 of the first and second arms 738 and 742. The first andsecond crimping forces will permanently deform the crimp members 752 ofthe frame 726 to thereby retain the spacer body 30 to the frame 726.Therefore, the instrument 1110 is configured to have a first position orconfiguration whereby the instrument receives the frame 726, and asecond position or configuration whereby the instrument applies acrimping force to the frame 726. It should be appreciated that theinstrument 1110 can also be used to crimp the frame 726 to the spacerbody.

As shown in FIGS. 14A and 14B, the instrument 1110 includes a first arm1118 and a second arm 1122 rotatably coupled to the first arm 1118 at afirst pivot 1126. The first and second arms 1118 and 1122 are configuredas crimping arms and each includes a handle portion 1130 that extendsproximally of the first pivot 1126 and a gripping portion 1134 thatextends distally of the first pivot 1126. The handle portions 1130 areconfigured to be gripped by an individual and moved toward each other tothereby crimp the frame 726 to the spacer body 30.

As shown in FIGS. 14A and 14B, the gripping portions 1134 are coupled tothe handle portions 1130 at respective second pivots 1138 that aredistal to the first pivot 1126. As shown in FIG. 14B, each grippingportion 1134 includes an extension member 1142 that extends from thesecond pivot 1138, and a gripping member 1146 that extends distally froma distal end of the extension member 1142. As shown, the grippingportions 1134 are coupled to each other at a third pivot 1150 thatproximate to the distal ends of the extension members 1142, such thatthe gripping members 1146 extend distally to the third pivot 1150.Therefore, when the handle portions 1130 are moved toward each other soas to rotate about the first pivot 1126, the extension members 1142 willrotate about their respective second pivots 1138 such that they moveaway from each other, and the gripping members 1146 will rotate aboutthe third pivot 1150 such that they move toward each other to therebycrimp the frame 726 on to the spacer body 30.

As shown in FIG. 14B, each gripping member 1146 defines a ribbed contactsurface 1156 that is configured to contact and apply a crimping force tothe crimp members 752 of the frame 726. As shown, the contact surfaces1156 are spaced apart from each other so as to define a void 1160 thatis configured to receive the frame 726 and spacer body 30. Each grippingmember 1146 may further define a lower platform that is configured tosupport the frame 726 and spacer body 30 while the instrument 1110 iscrimping the frame 726 to the spacer body 30. The ribs of the contactsurfaces 1156 are configured to allow a portion of the frame 26 betweenthe gripping members 1146.

In operation and in reference to FIG. 14C, the void 1160 defined betweenthe contact surfaces 1156 receives the frame 726 and spacer body 30 suchthat the spacer body 30 is loosely disposed within the frame 726. Bysqueezing the handle portions 1130 toward each other, the contactsurfaces 1156 will apply respective crimping forces to the crimp members752 of the frame 726. Once a sufficient amount of force has beenapplied, the crimp members 752 will permanently deform toward each othersuch that the frame 726 will move to the crimped or engaged position andwill provide a retention force against the spacer body 30 and retain thespacer body 30 to the frame 726. As shown, when in the crimped orengaged position, respective portions of the arms 738 and 742 are spacedapart from each other by the second distance d₂ which is less than thefirst distance.

In another embodiment and in reference to FIG. 14D, the instrument 1110can also be configured to bend the crimp members 952 of the frame 926.As shown, the instrument 1110 can include beaked protrusions 1170 thatare defined by the gripping members 1146 and are configured to engagethe crimp members 952 when the handle portions 1130 are squeezedtogether. The beaked protrusions 1170 can be anywhere along the grippingmembers 1146 so long as they align with the crimp members 952. Moreover,the gripping members 1146 can define any number of beaked protrusions1170, as desired. Therefore, if the frame 926 includes four crimpingtabs 956 (i.e. crimp members 952) then the gripping members 1146 caneach define two beaked protrusions 1170 that align with the crimpingtabs 956.

In another embodiment and in reference to FIGS. 15A and 15B frame mayinclude a fully enclosed endplate that supports the spacer body with amulti-walled, such as a six walled structure. As shown, anintervertebral implant frame 1226 includes a support member 1234, afirst arm 1238 that extends from the support member 1234, a second arm1242 that extends from the support member 1234, and an end plate 1244that connects the distal ends of the first and second arms 1238 and 1242together. The support member 1234, the first arm 1238, the second arm1242, and the end plate 1244 together define a six wall structure thatsupports the spacer body 30.

Now in reference to FIGS. 16A-16E, the spacer body 30 can be pre-drilledto make channels in the spacer body 30 using a spacer body drill guide1300. The channels are configured to provide clearance for the fixationelements 62 when the intervertebral implant is affixed to the superiorand inferior vertebral bodies. Therefore, when the fixation elements areinserted into the fixation element apertures of the frame and thensubsequently affixed to the vertebral bodies, the fixation elements willnot be interfered with by the spacer body 30. The channels can be madeeither before or after the spacer body has been retained by the frame.If the channels are made prior to the spacer body being retained by theframe, then the channels can have a dimension that is greater than adimension of the fixation element receiving apertures of the frame.

As shown in FIGS. 16A and 16B, the spacer body drill guide 1300 includesa clamp 1304 configured to hold the spacer body 30, and a cradle 1308that is configured to support the clamp 1304 while the channels aredrilled using a drill bit 1312. The clamp 1304 includes a first clamparm assembly 1316 and a second clamp arm assembly 1320 that is rotatablycoupled to the first clamp arm assembly 1316 at a first pivot 1324. Thefirst clamp arm assembly 1316 includes a first handle 1328, a firstextension member 1332, and a first jaw 1344 removeably coupled to thefirst extension member 1332. Similarly, the second clamp arm assembly1320 includes a second handle 1352, a second extension member 1356, anda second jaw 1358 removeably coupled to the second extension member1356. As shown, a proximal end of the first extension member 1332 iscoupled to a middle portion of the first handle 1328 at a respectivesecond pivot 1336, and a middle portion of the first extension member1332 is coupled to a distal end of the second handle 1352 at the thirdpivot 1340. Similarly, a proximal end of the second extension member1356 is coupled to a middle portion of the second handle 1352 at arespective second pivot 1336, and a middle portion of the secondextension member 1356 is coupled to a distal end of the first handle1352 at a respective third pivot 1340.

The first and second extension members 1332 and 1356 are substantiallyparallel to each other and remain substantially parallel to each otheras the first and second handles 1328 and 1352 are rotated about thefirst pivot 1324. This allows the first and second jaws 1344 and 1358 totranslate rather than rotate relative to each other as the first andsecond handles 1328 and 1352 are rotated about the first pivot 1324. Asshown in FIGS. 16A and 16B, each extension member 1332 and 1356 includesan elongate mounting portion 1370 at its distal end. Each mountingportion 1370 defines a fixation element receiving aperture 1364 that isconfigured to receive a respective fixation element 1374. As shown, thefirst and second jaws 1344 and 1358 are configured to be mounted to theremoveably mounting portions 1370 with the fixation elements 1374.

As shown in FIGS. 16A and 16B, the first jaw 1344 includes an elongatebody 1380 that has a proximal mounting portion 1384 and a distalgripping portion 1388. The mounting portion 1384 defines an elongatechannel 1392 that is configured to receive the mounting portion 1370 ofthe first extension member 1332. The mounting portion 1384 furtherdefines an outer slot or aperture 1396 that extends into the channel1392 and is configured to receive the fixation element 1374 to therebycouple the first jaw 1344 to the first extension member 1332. Themounting portion 1384 further includes an engagement rail 1397 that isconfigured to engage the cradle 1308 when the clamp 1304 is mounted tothe cradle 1308.

As shown in FIGS. 16A and 16B, the gripping portion 1388 includes aninner spacer contacting surface 1402, an outer surface 1406 and at leastone such as two, guide holes 1410 that extend from the outer surface1406 through to the inner spacer contacting surface 1402 at a downwardangle. The guide holes 1410 are configured to receive the drill bit 1312and guide the drill bit 1312 to the spacer body 30. As shown, a lowerportion of the inner spacer contacting surface 1402 defines a pair ofcut outs 1412 that provide clearance for the drill bit 1312 as itextends thought the holes 1410.

As shown in FIG. 16B, the gripping portion 1388 can further include amating member 1414, such as a bore 1418 that extends into the grippingportion 1388. The bore 1418 is configured to receive a mating member ofthe cradle 1308 to thereby properly align the clamp within the cradle.It should be appreciated that the mating member 1414 can have otherconfigurations as desired. For example, the mating member 1414 candefine a peg or protrusion.

As shown in FIGS. 16A and 16B, the second jaw 1358 includes an elongatebody 1430 that has a proximal mounting portion 1434 and a distalgripping portion 1438. The mounting portion 1434 defines an elongatechannel 1442 that is configured to receive the mounting portion 1370 ofthe first extension member 1332. The mounting portion 1434 furtherdefines an outer slot or aperture 1446 that extends into the channel1442 and is configured to receive the fixation element 1374 to therebycouple the second jaw 1358 to the second extension member 1356.

As shown in FIGS. 6A and 6B, the gripping portion 1438 includes an innerspacer contacting surface 1452, an outer surface 1456 and at least onesuch as two, guide holes 1460 that extend from the outer surface 1456through to the inner spacer contacting surface 1452 at a downward angle.The guide holes 1460 are configured to receive the drill bit 1312 andguide the drill bit 1312 to the spacer body 30. As shown, a lowerportion of the inner spacer contacting surface 1402 defines a pair ofcut outs 1462 that provide clearance for the drill bit 1312 as itextends thought the holes 1460.

As shown in FIG. 16B, each gripping portion 1388 and 1438 can furtherinclude a plurality of retention members 1470 that extend out from theinner spacer contacting surfaces 1402 and 1452. In the illustratedembodiment the retention members 1470 define spikes that are configuredto engage the spacer body 30. It should be appreciated, however, thatthe retention members 1470 can include other configuration, or thegripping portions 1388 and 1438 can be void of retention members 1470.

As shown in FIG. 16A, the cradle 1308 includes a base 1480 and amounting portion 1484 that extends up from the base 1480. The base 1480is sized and configured to sit on a surface and support the clamp 1304while the drill bit 1312 drills the channels into the spacer body 30.The mounting portion 1484 includes a transverse elongate body 1488 and achannel 1492 that extends transversely into the body 1488. The channel1492 is configured to receive the first jaw 1344 along a transversedirection such that when the first jaw 1344 is received by the channel1492 the first jaw 1344 is fully supported by the cradle 1308.

The mounting portion 1484 further includes a pair of drill guideapertures 1500 that extend through body 1488 and into the channel 1492.The drill guide apertures 1500 of the mounting portion 1484 areconfigured to align with the drill guide apertures 1410 of the first jaw1344 when the first jaw 1344 is received by the channel 1492. Themounting portion 1484 further includes a first platform 1504 that adistal end of the channel 1492 terminates into, and a mating member 1508that is defined by the first platform 1504. In the illustratedembodiment, the mating member 1508 is a peg 1512 that is configured tomate with the bore 1418 of the first jaw 1344. It should be appreciated,however, that the mating member 1508 can have other configurations asdesired so long as the mating members of the mounting portion 1484 andthe first jaw 1344 can mate with each other.

As shown in FIG. 16A, the cradle 1308 further includes a second platform1516 that extends from the base 1480 and is spaced apart from the firstplatform 1504. The second platform 1516 defines a pair of cutouts 1520that align with the drill guide apertures 1460 of the second jaw 1358when the second jaw 1358 is resting on the second platform 1516.

In operation and in reference to FIGS. 16C-16F, the clamp 1304 isconfigured to hold a spacer body 30 by moving the handle portions 1328and 1352 toward each other. The clamp 1304 is then translated toward thecradle 1308 subsequently along the transverse direction T such that thefirst jaw 1344 of the clamp 1304 is mounted within the channel 1492 ofthe cradle 1408. When mounted and as shown in FIG. 16D, the peg 1512engages the bore 1418, and the first and second jaws 1344 and 1358 reston the first and second platforms 1504 and 1516 respectively, such thatthe drill guide apertures 1410 of the first jaw 1344 are aligned withthe drill guide apertures 1500 of the cradle 1308.

As shown in FIG. 16E, the drill bit 1312 may then be inserted into thedrill guide apertures 1410 and 1460 to thereby form the channels in thespacer body 30. As shown in FIG. 16F, the spacer body 30 will have twoupper channels 1600, and two lower channels 1614. After the channelshave been formed, the spacer body 30 may be coupled to a frame such asone of the frames described, using any of the instruments described.When the spacer body 30 is retained by the frame the fixation elementreceiving apertures of the frame will align with the channels 1600 and1614 of the spacer body 30. The channels 1600 and 1614 can have adimension have a dimension such as a diameter d₄ that is greater thanthe diameter of the fixation element receiving apertures of the frame.It should be appreciated, however, that the diameter d₅ can be equal toor even less than the diameter of the fixation element receivingapertures of the frame, as desired.

It should be appreciated, that the drill guide 1300 can be part of a kitthat also includes at least one of an intervertebral implant frame, anactuation instrument, and a drill bit. Moreover is should beappreciated, that the kit can also include the spacer body 30 and atleast one fixation element 62.

In another embodiment and in reference to FIGS. 17A-17F, anintervertebral implant 1622 can include an intervertebral implant framethat is configured to be inserted into the intervertebral space suchthat a portion of the frame abuts an anterior surface 14 a of the firstvertebral body 10 a and a portion of the anterior surface 14 a issubstantially flush with or extends beyond a front face of the frame.The intervertebral implant 1622 includes similar structure as theintervertebral implant 22 shown in FIGS. 2A-3E and is configured tooperate in a similar manner unless otherwise described. For example, theintervertebral implant 1622 includes an intervertebral implant frame1626 and a spacer body 1630 that is retained by the frame 1626.

As shown in FIGS. 17C-17F the frame 1626 includes a support member 1634,a first arm 1638 that extends from the support member 1634, and a secondarm 1642 that extends from the support member 1634. In the illustratedembodiment, the first and second arms 1638 and 1642 are flexible armsthat extend from opposed ends of the support member 1634 such that thesupport member 1634, the first arm 1638, and the second arm 1642together create a three wall structure that retains and secures thespacer body 1630 to the frame 1626.

As shown in FIGS. 17C-17F, the support member 1634 includes a body 1646that defines a first vertebral body facing surface 1647, a secondvertebral body facing surface 1648 that is spaced from the firstvertebral body 1647 facing surface along a first direction, an innerface or surface 1650, and an outer or front face or surface 1654 that isspaced from the inner face along a second direction that issubstantially perpendicular to the first direction. The first and secondvertebral body facing surfaces 1647 and 1648 can be configured to atleast partially abut the first and second vertebral bodies when theimplant is implanted into the intervertebral space. It should beappreciated, however, that a portion of or the entirety of the first andsecond vertebral body facing surfaces 1647 and 1648 can be external tothe intervertebral space when the implant is implanted into theintervertebral space. It should be further appreciated, that the spacerbody 1630 can have a height that is greater than that of the arms suchthat first and second vertebral body facing surfaces 1746 and 1648 arespaced from the first and second vertebral bodies when the implant isimplanted into the intervertebral space. As shown in FIG. 17D, the body1646 can further define at least one, such as two or such as four,fixation element receiving apertures 1658 that extend through the body1646 from the front surface 1654 to the inner surface 1650. Eachfixation element receiving aperture 1658 is configured to receive arespective fixation element, such as fixation element 62 shown in FIGS.4A and 4B.

As shown in FIG. 17D, two of the fixation element receiving apertures1658 are inner apertures 1668 that extend through the body 1646 at adownward angle relative to the insertion direction I, and two of thefixation element receiving apertures 1658 are outer apertures 1670 thatextend through the body 1646 at an upward angle relative to theinsertion direction I. The inner apertures 1668 are configured toreceive respective fixation elements, such as fixation element 62 shownin FIGS. 4A and 4B, to thereby attach the intervertebral implant 1622 tothe inferior vertebral body 10 b. Similarly, the outer apertures 1670are configured to receive respective fixation elements 62 to therebyattach the intervertebral implant 1622 to the superior vertebral body 10a. It should be appreciated, however, that the inner apertures 1668 canextend through the body 1646 at an upwards angle and the outer apertures1670 can extend through the body 1646 at a downwards angle, as desired.Moreover, it should be appreciated that the support member 1634 candefine any number of fixation element receiving apertures 1658 asdesired.

As shown in FIG. 17D, the apertures 1658 each define internal threads1678. The internal threads 1678 are configured to engage externalthreads 80 defined by a head 82 of the respective fixation element 62that is received within the apertures 1658. It should be appreciated,however, that the apertures 1658 can be void of threads as desired. Theorientation of the apertures 1658 may be configured such that thefixation elements that are received by the apertures 1658 may have aninsertion variance of +/−5 degrees and do not allow toggling orsettling. Once fully received, the fixation elements may lock to theframe 1626 to thereby increase the surgeon's reassurance of good screwtrajectories and can act as a safety by preventing possibilities ofover-insertion during implantation.

As shown in FIGS. 17C and 17D, the support member 1634 can include atleast a first tab 1664 a and a second tab 1664 b that extend from thefirst vertebral body facing surface 1647 along a common direction, suchas along the first direction, such that first tab 1664 a and the secondtab 1664 b are spaced from each other along a second direction that issubstantially perpendicular to the first direction so as to define a gap1665 a between the first and second tabs 1664 a and 1664 b. As shown inFIGS. 18A-18C, the gap 1665 a is sized or otherwise configured toreceive a portion of the first vertebral body when the first and secondarms 1638 and 1642 are inserted into the intervertebral space. As shownin FIG. 17D, the first tab is spaced from second tab 1664 b by a firstdistance G₁. The first distance G₁ can be any distance so long as aportion of the first vertebral body can extend into the gap 1665 a.

With continued reference to FIGS. 17C and 17D, the support member 1634can further include a third tab 1664 c and a fourth tab 1664 d thatextend from the second vertebral body facing surface 1648 along a commondirection, such as along the first direction, and away from the firstand second tabs 1664 a and 1664 b such that the third tab 1664 c andfourth tab 1664 d are spaced from each other along the second directionso as to define a gap 1665 b between the third and fourth tabs 1664 cand 1664 d. The gab 1665 b between the third and fourth tabs 1664 c and1664 d is configured to receive a portion of the second vertebral bodywhen the first and second arms 1638 and 1642 are inserted into theintervertebral space. As shown in FIG. 17D, the third tab 1664 c isspaced from fourth tab 1664 d by a second distance G₂. The seconddistance G₂ can be any distance so long as a portion of the secondvertebral body can extend into the gap 1665 b. As shown, the seconddistance G₂ can be less than the first distance G₁. It should beappreciated, however, that the first and second distances G₁ and G₂ cansubstantially the same or the second distance G₂ can be greater than thefirst distance G₁, as desired. The first and second tabs can beequidistant from a centerline of the frame and the third and fourth tabscan be equidistant from the centerline of the frame. It should beappreciated, however, that

Each of the tabs 1664 a-1664 d defines a front surface 1666 a and anopposed bone contacting surface 1666 b. The front surfaces 1666 a ofeach tab 1664 a-1664 d can be flush with or otherwise coincident withthe front face 1654 as illustrated. It should be appreciated, however,that the front surfaces 1666 a can be offset with respect to the frontface 1654, as desired. The bone contacting surfaces 1666 b of the firstand second tabs 1664 a and 1664 b are configured to abut the firstvertebral body and bone contacting surfaces 1666 b of the third andfourth tabs 1664 c and 1664 d are configured to abut the secondvertebral body when the first and second arms 1638 and 1642 are insertedinto the intervertebral space. When the frame is implanted into theintervertebral space, anterior surfaces of the first and secondvertebral bodies can be flush with or extend beyond the front faces ofthe tabs.

As shown in FIGS. 17A-17C, the first arm 1638 and the second arm 1642each extend from the support member 1634 and define a first distalterminal end 1683 and a second distal terminal end 1684, respectively.The first and second arms 1638 and 1642 each define a proximal portion1685 and a distal portion 1686. The proximal portions 1685 are narrowedso that the first and second arms 1638 and 1642 can flex. The distalportions 1686 can be configured as support portions that define firstand second vertebral body contacting surfaces that contact the vertebralbodies so as to support the vertebral bodies 10 a and 10 b relative toeach other. The arms 1638 and 1642 can be similar to the arms 38 and 42and can define first and second lengths that are between about 50% andabout 100% of an anterior-posterior length of the intervertebral space.As illustrated, the arms 1638 and 1642 have a length that is less thanthe lengths of the arms 38 and 42. It should be appreciated, however,that the arms 1638 and 1642 can have any lengths as desired. The firstarm 1638 includes a first inner spacer contacting surface 1688 and thesecond arm 1642 includes a second inner spacer contacting surface 1692that is spaced from the first inner spacer contacting surface 1688 alongthe second direction, such as the lateral direction A. The inner surfaceof the support member 1634, the first inner spacer contacting surface1688, and the second inner spacer contacting surface 1692 togetherdefine a void 1694 that is configured to receive and grip a spacer body1630, such as a spacer body 1630 consisting of cancellous bone.

As shown in FIGS. 17E and 17F, the first and second arms 1638 and 1642extend from the support member 1634 such that the first and second arms1638 and 1642 are angled toward each other so as to push the spacer body1630 toward the other of the first and second arms 1638 and 1642 andtoward the support member 1634. For example, the inner surface 1650 ofthe support member 1634 and the first inner spacer contacting surface1688 form an angle Θ_(A) that is less than 90 degrees, and the innersurface 1650 of the support member 1634 and the second inner spacercontacting surface 1692 form an angle θ_(B) that is less than 90degrees.

As shown in FIG. 17F, each arm 1638 and 1642 can further include awindow 1756 that extends laterally through the arms 1638 and 1642. Thewindows 1756 are configured to provide visual access to the spacer body1630 through the first and second arms 1638 and 1642 when the frame 1626is retaining the spacer body 1630. As shown, the windows 1756 are ovalshaped and elongate along the longitudinal direction L. It should beappreciated, however, that the windows 1756 can have any shape asdesired. For example, the windows 1756 can also be rectangular shaped.

As shown in FIGS. 17C and 17F, each arm 1638 and 1642 includes anengagement member 1770 that is configured to receive a first and asecond external expansion force, respectively, from an expansioninstrument prior to insertion of the spacer body 1630 into the void 1694such that at least one of the first and second arms 1638 and 1642elastically expands or elastically flexes with respect to the other ofthe first and second arms 1638 and 1642 in response to the expansionforces. As shown in FIG. 17C, the engagement members 1770 each define adove-tailed slot 1774 that defines an opening 1778 at its distal endsuch that the expansion instrument can engage the dove-tailed slot 1774in a direction that is opposite to the insertion direction I of theframe 1626. It should be appreciated, however, that the engagementmembers 1770 can have any configuration as desired so long as they canreceive respective expansion forces.

Now in reference to FIGS. 18A and 18B, the tabs 1664 a-1664 d are spacedrelative to each other so as to allow at least a portion of an anteriorsurface or end E of at least one of the first and second vertebralbodies to be substantially flush with or extend beyond the front face1654 of the support member 1634 when the bone contacting surfaces 1666 bof at least one such as all of the tabs 1664 a-1664 d abut the anteriorsurfaces or ends E of the first and second vertebral bodies 10 a and 10b. In the illustrated embodiment and as shown in FIG. 18A, the gapbetween the first and second tabs 1664 a and 1664 b and the gap betweenthe third and fourth tabs 1664 c and 1664 d are each sized such thatwhen the first and second arms 1638 and 1642 are inserted into theintervertebral space the at least a portions of the first and secondvertebral bodies extend through the gaps 1665 a and 1665 b and beyondthe front face 1654. Because vertebral bodies 10 a and 10 b are flushwith and/or extend beyond the front face 1654, it can be said that theframe 1626 provides a zero profile at a centerline of the vertebralbodies when the arms 1638 and 1642 are inserted into the intervertebralspace.

In use, the intervertebral implant can be inserted into theintervertebral space until the spacer body is disposed in theintervertebral space such that opposed first and second surfaces of thespacer body face respective ones of the first and second vertebralbodies. A common one of the first and second vertebral bodies can beabutted with each of the first and second tabs. And, a portion of thecommon one of the first and second vertebral bodies is caused to extendat least through a gap that extends between the first and second tabs. Acommon one of the first and second vertebral bodies can also be abuttedby the third and fourth tabs. And, a portion of the common one of thefirst and second vertebral bodies can be caused to extend at leastthrough a gap that extends between the third and fourth tabs. It shouldbe appreciated that the implant can be prepackaged with the frameretaining the spacer body or the frame can be configured to retain thespacer body immediately prior to insertion into the intervertebralspace. It should be appreciated that the spacer body can be synthetic ormade of allograft bone.

For example, the first and second arms can be moved from a firstposition to a second position, whereby first and second spacercontacting surfaces of the first and second arms, respectively, arespaced apart by a first distance when in the first position, and arespaced apart by a second distance that is greater than the firstdistance when in the second position. The allograft spacer body can thenbe inserted into the frame between the first and second arms when thefirst and second arms are in the second position. The first and secondarms can then be moved to a third position, whereby the first and secondspacer contacting surfaces are spaced apart by a third distance when inthe third position, the third distance is less than the second distancesuch that the arms apply a retention force against the allograft spacerbody to thereby retain the allograft spacer body in the frame. Once theimplant is inserted into the intervertebral space respective boneanchors can be inserted through the apertures of the frame and into therespective first and second vertebral bodies to thereby attach theimplant to the first and second vertebral bodies.

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. Furthermore, it should be appreciated thatthe structure, features, and methods as described above with respect toany of the embodiments described herein can be incorporated into any ofthe other embodiments described herein unless otherwise indicated. Forexample, the frame 1626 can also include crimp members as shown in FIGS.10A, 11A, 12A, and 13A. It is understood, therefore, that this inventionis not limited to the particular embodiments disclosed, but it isintended to cover modifications within the spirit and scope of thepresent disclosure. Further, it should be appreciated, that the termsubstantially indicates that certain directional components are notabsolutely perpendicular to each other and that substantiallyperpendicular means that the direction has a primary directionalcomponent that is perpendicular to another direction.

What is claimed:
 1. An intervertebral implant frame configured tosupport a spacer body in an intervertebral space that is defined by afirst vertebral body and a second vertebral body, the intervertebralimplant frame comprising: a support member having a body that definesfirst and second vertebral body facing surfaces, the second vertebralbody facing surface spaced from the first vertebral body facing surfacealong a first direction, the body further defining at least two fixationelement receiving apertures that extend through the support member andare each configured to receive a respective bone fixation element, afirst tab and a second tab that each extend from the first vertebralbody facing surface and are spaced from each other along a seconddirection that is substantially perpendicular to the first direction soas to define a gap that extends between the first and second tabs alongthe second direction, each of the first and second tabs being configuredto abut the first vertebral body when the intervertebral implant isinserted in the intervertebral space; first and second arms arm thatextend from the support member and include, respectively, a first innerspacer contacting surface and a second inner spacer contacting surfacethat is spaced from the first inner spacer contacting surface along thesecond direction such that the first arm and the second arm areconfigured to grip and retain the spacer body, wherein the gap isconfigured to receive a portion of the first vertebral body when each ofthe first and second tabs abuts the first vertebral body.
 2. Theintervertebral implant frame of claim 1, wherein the support memberfurther includes third and fourth tabs that each extend from the secondvertebral body facing surface along the first direction and away fromthe first and second tabs such that the third tab and the fourth tab arespaced from each other along the second direction so as to define a gapbetween the third and fourth tabs.
 3. The intervertebral implant frameof claim 2, wherein the gap between the third and fourth tabs isconfigured to receive a portion of the second vertebral body when thefirst and second arms are inserted into the intervertebral space.
 4. Theintervertebral implant frame of claim 3, wherein the first and secondtabs each defines a bone contacting surface that is configured to abutthe first vertebral body when the first and second arms are insertedinto the intervertebral space, and the third and fourth tabs eachdefines a bone contacting surface that is configured to abut the secondvertebral body when the first and second arms are inserted into theintervertebral space.
 5. The intervertebral implant frame of claim 4,wherein the support member body defines a front face and an inner facespaced from the front face along a third direction that is substantiallyperpendicular to the first and second directions, and wherein the gapbetween the first and second tabs and the gap between the third andfourth tabs are each sized such that when the first and second arms areinserted into the intervertebral space portions of the first and secondvertebral bodies extend through the gaps and beyond the front face. 6.The intervertebral implant frame of claim 3, wherein the first tab isspaced from the second tab along the second direction by a firstdistance, and the third tab is spaced from the fourth tab along thesecond direction by a second distance that is less than the firstdistance.
 7. The intervertebral implant frame of claim 1, wherein thefirst and second arms are capable of retaining a spacer body consistingof cancellous bone.
 8. The intervertebral implant frame of claim 1,wherein the first arm and the second arm are angled toward each othersuch that an inner face of the support member and the first inner spacercontacting surface forms an angle that is less than 90°, and the innerface of the support member and the second inner spacer contactingsurface forms an angle that is less than 90°.
 9. The intervertebralimplant frame of claim 1, wherein the first and second arms define firstand second lengths that are between about 50% and 100% of ananterior-posterior length of the intervertebral space.
 10. Theintervertebral implant frame of claim 1, wherein the first and secondtabs have an equidistant spacing from a centerline of the frame.
 11. Theintervertebral implant frame of claim 1, wherein the first and secondarms each include an expansion instrument engagement member.
 12. Theintervertebral implant frame of claim 11, wherein the expansioninstrument engagement members each define a dove-tailed slot.
 13. Theintervertebral implant frame of claim 12, wherein the dove-tailed slotsare each open at their distal ends, such that an expansion instrumentcan engage the dove-tailed slots in a direction that is opposite to aninsertion direction of the intervertebral implant frame.
 14. Theintervertebral implant frame of claim 1, wherein at least one of thefirst and second arms is configured to elastically expand with respectto the other of the first and second arms in response to an expansionforce.
 15. The intervertebral implant frame of claim 1, furthercomprising at least one tab that extends from the second vertebral bodyfacing surface along the first direction,
 16. The intervertebral implantframe of claim 15, wherein the support member body defines an inner faceand a front face spaced from the inner face along a third direction thatis substantially perpendicular to the first and second directions, andwherein the at least two tabs and the at least one tab are spacedrelative to each other so as to allow at least a portion of an anteriorsurface of at least one of the first and second vertebral bodies to besubstantially flush with or extend beyond the front face of the supportmember body.
 17. The intervertebral implant frame of claim 15, whereineach tab defines a bone contacting surface and a front face spaced fromthe bone contacting surface along a third direction that issubstantially perpendicular to the first and second directions, andwherein the at least two tabs and the at least one tab are spacedrelative to each other so as to allow at least a portion of an anteriorsurface of at least one of the first and second vertebral bodies to besubstantially flush with or extend beyond the front faces of the tabswhen the bone contacting surfaces of the tabs abut the anterior surfacesof the first and second vertebral bodies.
 18. A method of implanting anintervertebral implant into an intervertebral space defined by first andsecond vertebral bodies, the intervertebral implant including a supportmember body, first and second tabs that extend in a common directionfrom the support member body, first and second arms arm that extend fromthe support member body, and a spacer body gripped between the first andsecond arms, the method comprising the steps of: inserting theintervertebral implant into the intervertebral space until the spacerbody is disposed in the intervertebral space such that opposed first andsecond surfaces of the spacer body face respective ones of the first andsecond vertebral bodies; abutting a common one of the first and secondvertebral bodies with each of the first and second tabs; and causing aportion of the common one of the first and second vertebral bodies toextend at least through a gap that extends between the first and secondtabs.
 19. The method of claim 18, further comprising the steps of movingthe first and second arms from a first position to a second position,whereby first and second spacer contacting surfaces of the first andsecond arms, respectively, are spaced apart by a first distance when inthe first position, and are spaced apart by a second distance that isgreater than the first distance when in the second position; insertingan allograft spacer body into the frame between the first and secondarms when the first and second arms are in the second position; andmoving the first and second arms to a third position, whereby the firstand second spacer contacting surfaces are spaced apart by a thirddistance when in the third position, the third distance is less than thesecond distance such that the arms apply a retention force against theallograft spacer body to thereby retain the allograft spacer body in theframe.
 20. The method of claim 18, wherein apertures extend through thesupport member body, the method further comprising the step of insertingrespective bone anchors through the apertures and into the respectivefirst and second vertebral bodies.
 21. The method of claim 18, whereinthe frame further includes third and fourth tabs that extend in a commondirection from the support member body, the method further comprisingthe steps of abutting a common one of the first and second vertebralbodies with each of the third and fourth tabs; and causing a portion ofthe common one of the first and second vertebral bodies to extend atleast through a gap that extends between the third and fourth tabs.